Shrouded turbofan bleed duct

摘要

A bleed duct (42) is configured for bleeding fan air from the fan bypass duct (32) in a turbofan aircraft engine (10). The bleed duct (42) includes a tubular conduit (48) having an inlet (50) and outlet (52) at opposite ends. The conduit (48) is configured in flow area for recovering pressure from speeding fan air bled therethrough. A shroud (60,68,70,72,74) extends forwardly from the duct inlet (50) for suppressing dynamic pressure oscillations inside the conduit (48) without degrading the pressure recovery.